Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Multiple Redox Modes in the Reversible Lithiation of High-Capacity, Peierls-Distorted Vanadium Sulfide
AU - Britto, Sylvia
AU - Leskes, Michal
AU - Hua, Xiao
AU - Hébert, Claire-Alice
AU - Shin, Hyeon Suk
AU - Clarke, Simon
AU - Borkiewicz, Olaf
AU - Chapman, Karena W.
AU - Seshadri, Ram
AU - Cho, Jaephil
AU - Grey, Clare P.
PY - 2015/7/8
Y1 - 2015/7/8
N2 - Vanadium sulfide VS4 in the patronite mineral structure is a linear chain compound comprising vanadium atoms coordinated by disulfide anions [S2]2–. 51V NMR shows that the material, despite having V formally in the d1 configuration, is diamagnetic, suggesting potential dimerization through metal–metal bonding associated with a Peierls distortion of the linear chains. This is supported by density functional calculations, and is also consistent with the observed alternation in V–V distances of 2.8 and 3.2 Å along the chains. Partial lithiation results in reduction of the disulfide ions to sulfide S2–, via an internal redox process whereby an electron from V4+ is transferred to [S2]2– resulting in oxidation of V4+ to V5+ and reduction of the [S2]2– to S2– to form Li3VS4 containing tetrahedral [VS4]3– anions. On further lithiation this is followed by reduction of the V5+ in Li3VS4 to form Li3+xVS4 (x = 0.5–1), a mixed valent V4+/V5+ compound. Eventually reduction to Li2S plus elemental V occurs. Despite the complex redox processes involving both the cation and the anion occurring in this material, the system is found to be partially reversible between 0 and 3 V. The unusual redox processes in this system are elucidated using a suite of short-range characterization tools including 51V nuclear magnetic resonance spectroscopy (NMR), S K-edge X-ray absorption near edge spectroscopy (XANES), and pair distribution function (PDF) analysis of X-ray data.
AB - Vanadium sulfide VS4 in the patronite mineral structure is a linear chain compound comprising vanadium atoms coordinated by disulfide anions [S2]2–. 51V NMR shows that the material, despite having V formally in the d1 configuration, is diamagnetic, suggesting potential dimerization through metal–metal bonding associated with a Peierls distortion of the linear chains. This is supported by density functional calculations, and is also consistent with the observed alternation in V–V distances of 2.8 and 3.2 Å along the chains. Partial lithiation results in reduction of the disulfide ions to sulfide S2–, via an internal redox process whereby an electron from V4+ is transferred to [S2]2– resulting in oxidation of V4+ to V5+ and reduction of the [S2]2– to S2– to form Li3VS4 containing tetrahedral [VS4]3– anions. On further lithiation this is followed by reduction of the V5+ in Li3VS4 to form Li3+xVS4 (x = 0.5–1), a mixed valent V4+/V5+ compound. Eventually reduction to Li2S plus elemental V occurs. Despite the complex redox processes involving both the cation and the anion occurring in this material, the system is found to be partially reversible between 0 and 3 V. The unusual redox processes in this system are elucidated using a suite of short-range characterization tools including 51V nuclear magnetic resonance spectroscopy (NMR), S K-edge X-ray absorption near edge spectroscopy (XANES), and pair distribution function (PDF) analysis of X-ray data.
U2 - 10.1021/jacs.5b03395
DO - 10.1021/jacs.5b03395
M3 - Journal article
VL - 137
SP - 8499
EP - 8508
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 26
ER -